For years, we have heard of the depletion of IPv4 address space on the Internet. At the same time, more and more networks are coming online. Out of these new networks, we have an ever-increasing number wanting to participate in BGP routing. This can be for several reasons. The first is for what BGP was designed for autonomy. Companies are not at the mercy of a single provider for critical infrastructure. If you have ever had to switch providers with IP addresses from...
Continue reading...BGP
Problems with Borger Gateway Protocol (BGP)
Border Gateway Protocol (BGP) is the Internet’s dominant inter-domain routing protocol, and as such, it is a critical component of the Internet’s infrastructure. However, BGP, like any other technology, has flaws. The following are some of the most common BGP issues: Some of the above issues are being addressed with RPKI, Routing Registries, and MANRS, to name a few. In conclusion, while BGP is a critical component of the Internet’s infrastructure, it is not without its challenges. Network operators and administrators need to...
Continue reading...Border Gateway Protocol (BGP) in a nutshell
I have been busy writing some posts on some general topics for those readers who want some high-level overviews of various network terms and items. Border Gateway Protocol (BGP) is the core routing protocol used to exchange information about network reachability between routers in the Internet. BGP enables routers to make informed decisions about the routes to reach specific destinations, ensuring that internet traffic is delivered efficiently and reliably. Here are some key points about BGP: In conclusion, Border Gateway Protocol (BGP) is...
Continue reading...The Mess we call BGP
Ever wonder why BGP seems to be such a complicated protocol to administer? It seems pretty straightforward to set up. Some commands, and you have a BGP session. Easy huh? BGP is one of those things where the more BGP feeds you bring in, the more complex traffic management becomes. Why? Take a look at the following graphic. What you are looking at is a small visualization of some of the AS connections to Hurricane Electric (AS6939) in North America. This is not...
Continue reading...A tool to find out if BGP is lying to you
APNIC has a bog article on detecting “bgp lies”. https://blog.apnic.net/2021/05/24/a-tool-to-detect-bgp-lies/Do you ever wonder whether you can really trust other networks, such as your provider(s) and peers? More precisely, wouldn’t you like to be able to tell if the traffic you send always flows through the paths received in the Border Gateway Protocol (BGP)? Could it be that, for some prefixes, the forwarding path might differ?
Continue reading...Proper BGP DENY-ALL filter for mikrotik
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Continue reading...BGP, a single /24 and two diverse non-connected exit points
I am starting to see the following scenario more and more as IPv4 space is hard to get, but isn’t. With ARIN it is still possible to get an IPv4 allotment. Many smaller ISPs qualify for a /24 and can get one if they wait long enough on the ARIN waiting list. a /24 of IPv4 space is the smallest block that 99% of the Internet allows to be advertised on the Capital I Internet. There are filter rules in place that drop...
Continue reading...Mikrotik Connection tracking and CPU usage
This content is for Patreon subscribers of the j2 blog. Please consider becoming a Patreon subscriber for as little as $1 a month. This helps to provide higher quality content, more podcasts, and other goodies on this blog.To view this content, you must be a member of Justin’s Patreon Unlock with PatreonAlready a qualifying Patreon member? Refresh to access this content.
Continue reading...ARIN IRR Walkthrough
https://www.arin.net/announcements/20200728/ ARIN Internet Routing Registry walkthrough.
Continue reading...FD-IX: Local-pref and default routes
I just finished up an article over on the FD-IX blog about local-prefs, default routes, and Internet exchanges. https://www.fd-ix.com/uncategorized/local-pref-and-default-routes/ Not everyone on the Internet needs full feeds from their provider. In this case, how does learning routes from an Internet Exchange such as FD-IX benefit you if all you are doing is default routes? So let’s take a scenario. You are a local hosting company. You don’t provide Internet to customers, you just do hosting of websites and data. You have a couple...
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